You know, your drawing of Amaura kinda brings me to something here. Work on blending a little more. Right now, Amaura's fins don't transition from yellow to pink smoothly, they're just sort of sitting next to each other. So next time try to blend out your colors a bit. It requires a soft touch to combine two colors without muddying them, but I think once you have a good grasp on that, you'll be able to apply that skill to things like shading, where you'll really be able to capture depth in your drawings.
That's all. Just a quick tidbit that I just noticed. Carry on. :)